The National Research Council's (NRC) Committee on Animal Nutrition proposes to convene a subcommittee to revise 1985 and 1986 publications on Nutrient Requirements of Dogs and Nutrient Requirements of Cats. Recognizing the value of convening dog and cat nutrition experts to deliberate simultaneously, the study will be conducted as a single project and these two publications will be revised in a single report, with separate volumes, if desirable. The new revision will provide updated estimates of requirements for all nutrients and will contain discussions of nutrient metabolism, toxicity, deficiency, and nutritionally- related disease in both dogs and cats. Information on the impacts of physiologic status, temperature, breed, age, and environment on nutrient requirements also will be included. The revised report will address unique biologic characteristics affecting nutrient digestion and utilization. General considerations regarding feed ingredients, diet formulation, feed processing and manufacturing will be presented. Principles of feeding research animals, working and service animals, and pets will be addressed. The report will provide practical recommendations on nutrient requirements of dogs and cats. It is anticipated that this study will be conducted over a 36-month period. The principal investigator and project assistants will assist the appointed experts in all phases of the project. The report will be subject to NRC public information and review procedures and will be printed and distributed by the National Academy Press.